input中的oninput不执行JavaScript

本人新手，想要做到输入采购数量后运费自动更新，所以在采购数量的input中使用了oninput="searchFreight()"，但是测试的时候发现没有反应，请问是什么原因呢？

采购数量：

                        <div class="pe-box">
                            <input type="text" 
                                   oninput="searchFreight()"
                                   class="ui-input goodsCount"
                                   placeholder="至少采购10吨以上"
                                   data-bind="value:caigouTon"
                                   id="goodsCount"
                                   name="goodsCount"
                                   style="width: 150px;" />
                            <span class="pe-n">吨</span>
                        </div>
                    </div>

//运费查询
function searchFreight(){
hsFramework.getJSON(urls.host+'actualStuffMall/query/queryTransportFee.do',{
goodsCount:this.caigouTon(),
deliveryPortId:deliveryPortId,
fromProvinceId:fromProvinceId,
fromCityId:fromCityId,
fromAreaId:fromAreaId,
fromStreetId:fromStreetId,
toProvinceId:vm.provinceId(),
toCityId:vm.cityId(),
toAreaId:vm.countyId(),
toStreetId:vm.streetId(),
toCommunityId:vm.communityId()
},function (data) {
var body = data.body;
var feePrice = body.feePrice;
var startPrice = body.startPrice;
var c;
if(feePrice==null){
// document.getElementById(".tips").style.visibility="hidden";//隐藏
c="收货地址不在配送范围之内，您仍可继续下单，后续将有交易员和您线下沟通其他配送方式。"
}else{
// document.getElementById(".tips").style.visibility="visible";//显示

c = '运费: '+feePrice+'元/吨(起步价:'+startPrice+'元)';
}
vm.feePrice(c);
});
}